Networking with Ubuntu 8.04 and Windows, Part III - page 2

Sharing Files in Ubuntu

July 16, 2008

By
Eric Geier

Dealing with folder and sharing permissions can get down right confusing, so let's summarize the different sharing permission scenarios we've already figured out how to apply through the Folder Sharing dialog box:

Users have read-only access, no editing: When you share a folder, as just discussed, you can leave the permission settings alone by not marking the two optional check boxes. This means everyone on the network that has a SMB password set up can access the folder, but can't make any changes. Of course, the user that shared the folder has full access.

Users have read/write access: Marking the second check box, on the Folder Sharing dialog box, gives the users the privilege of editing the files in the folder.

Guests receive read access: The third check box, on the Folder Sharing dialog box, lets you offer guest access (without editing rights) to users that don't have a SMB password. Marking both options gives everyone, even people with out an account, privileges to make changes to the files in the folder.

Everyone (including guests) has read/write access: This is achieved when you mark both the second and third check boxes on the Folder Sharing dialog box. This option is not recommended for wireless networks unless you have a highly secure network, for example if you are using WPA encryption.

Setting Advanced Sharing Permissions

You can edit the advanced permissions by right-clicking the folder you shared and selecting Properties, and then by clicking the Permissions tab. You'll see options similar to what's shown in Figure 2. You can configure a separate access type for the Owner, Group, and Others. Selecting None or List Only Files wouldn't give any access of the folder to the particular party, choosing Access Files gives read-only access, and Create and Delete Files would give complete access.

Fiddling around with the permission settings for the Group and Others gives you a few more useful sharing permission scenarios:

No one has access, except for folder owner: This option is typically the best way to share folders that you don't want others messing with; only you can see and edit them. This is achieved by selecting None for the Folder Access of the Others and Group categories.

General users have no access; accounts belonging to a certain group have read/write access: This scenario is a great way to share folders only to specific users. For example, you could create a Parents or Management group so you can share files between only you and your spouse or you and others on the management team, keeping your children or employees in the dark. Achieving this scenario consists of choosing None for the Folder Access of the Others and selecting Create and Delete Files for the Folder Access of Group. Then you would select the Group you want to apply the permission to. If you haven't set up Groups yet, you would want to reference the next sections before implementing this scenario.

General users have read-only access; accounts belonging to a certain group have read/write access: You can implement this scenario by selecting Access Files for the Folder Access of Others and choosing Create and Delete Files for the Folder Access of Group. As with the previous option involving Groups, you first need to create and assign groups for your Ubuntu accounts using the sections that follow, and then you can select the Group you want to apply the permission to.

Creating and Assigning Groups for Your Accounts

If you want to use a sharing permission scenario involving Groups, as discussed in the last two bullets of the previous section, you must first create Groups. Then you can assign accounts to these Groups, letting you set unique sharing permissions to a select number of accounts. Creating the Groups is a simple task; just follow these steps:

Click System | Administration | Users and Groups.

On the User Settings window, click the Unlock button, choose an Administrator account, enter the account password, and click the Authenticate button.

On the User Settings window, click the Manage Groups button.

Click the Add Group button (see Figure 3), and on the New Group dialog box, enter a Group Name and select the accounts you want to be in the group, and click OK.

Now you can use Groups when setting permissions for your shared folders.